Automatic shutoff device



Nov. 29, 1949 t 'r. E. PARRISH 2,489,461

I AUTOMATIC SHUTOFF DEVICE Filed Oct. 2, 1948 n \xunuxnuun INVENTOR- TOME. PARR/SH fizwrgm za ATTORNEY Patented Nov. 29, 1949 UNITED STATESPATENT OFFICE AUTOMATIC SHUTOFF DEVICE Tom E. Parrish, Beaumont, Tex.

Application October 2, 1948, Serial No. 52,549

device for use in connection with a battery of one or more tanks such asthose commonly used 1 Claim. ((11. 137-68) in oil pipe line gatheringsystems. It is common practice to pump oil from two or more of suchtanks at the same time, the draw-off lines from the several tanks beingserved by a common pipe line. Ordinarily the liquid level in the severaltanks of the battery becomes equalized dur-,

ing pumping. A pipe line may be fed by a number of such batteries oftanks, taking suction on all of them at the same time. The shutoffdevice of this invention may be used to shut off the flow of liquid froma given tank or battery when the liquid level therein has dropped belowa certain point, such, for example, as the point where the draw-off lineenters the tank. At the same time the connection between the drawoffline and the pipe line is positively closed so that no air is admittedto the pipe line from the tank.

A number of devices intended to be used for the purpose described arenow on the market, and others are disclosed in previously issuedpatents, but none of them are entirely satisfactory.

In my copending application, Serial No. 714,819, filed December '7,1946, I have disclosed and claimed an automatic shutoff device forliquid conducting lines. The automatic shutoff device described in thisapplication is an improvement over the one disclosed in my copendingapplication.

It is an object of the invention to provide an automatic shutolT devicewhich is adapted to shut off the flow of liquid from a tank withoutpermitting any air whatsoever to enter the pipe line from the tank. Thepresence of air in a pipe line destroys the suction and thus interfereswith the pumping operation.

It is a further object of the invention to provide a float controlledshutoff valve which is fully automatic and is so designed that the floatwill rise and fall freely in response to fluctuations in liquid leveland the valve will be properly seated.

The invention will be readily understood by referring to the followingdescription and the accompanying drawing, in which:

Fig. 1 is a diagrammatic view in elevation showing one of a battery oftanks having its drawoif line connected to a header which may be theinvention interposed between the header and the pipe line.

. Fig. 2 is a sectional view in elevation of the shutofi device, showingthe valve in open posis tion.

Fig. 3 is a sectional View taken on the line 3-3 of Fig. 2.

Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2.

Referring to the drawing, the numeral I indicates a tank which isconnected thru valved draw-off line 2 to a header 3. The tank I issituated above the ground, while the header 3 is buried below thesurface. A riser 4 connects the header 3 with the shutoff device of theinvention, which is indicated generally by the numeral 5. The shutoffdevice 5 is connected by a discharge pipe 5 to a pipe line (not shown).

The shutoff device 5 comprises a vertically disposed cylindrical casingI which is of relatively large diameter and provides a float chamber ofconsiderable cross sectional area. An inlet pipe 8 and an outlet pipe 9enter the casing from the bottom and extend upwardly a short distancetherefrom.

A cylindrical float I0 is received bodily within the casing I. A valvedisc II is connected at its center thru a ball joint I2 to the lower endof a valve stem I3 which extends upwardly thru the float ID. The floatIt! is rigidly secured to. the valve stem I3. upwardly above the floatIE! and the upward ex-. tension thereof, indicated by the numeral I4,acts as a guide rod.

shown), with the automatic shutofi device of The diameter of the floatI0 is only slightly less than the inside diameter of the casing I. Aplurality of resilient, spring-like guides I5 are attached to the lowerend of the float ID and extend outwardly therefrom to engage the innerwall of the casing I.

The valve disc I I preferably is made of a tough,

resilient, rubber-like material such as neoprene, and is of relativelylarge diameter. It is adapted. to cover the ends of both the inlet pipe8 and the outlet pipe 9. The arrangement is such, how-j. ever, that onlythe outlet pipe 9 is closed by.

operation of the valve disc II. The upper end of the outlet pipe 9 isslightly higher than that of the inlet pipe 8 and terminates in a. metalring I6, which may be made of Monel or other, suitable metal and whichfunctions as a valveseat.

The top of the casing 1 is formed by a blind flange I? which is securedto the upper end of; the casing I by bolts I8. A vent pipe I9 extendsThe valve stem I3 extends.

seat 28 may be made of brass.

thru the center of the flange I1 and is provided at its outer end with astopcock 29. A valve housing 2i is connected at its upper end to thelower end of the vent pipe IS. A short nipple '22 is connected at itsupper end to the lower end of the valve housing 2|, and a sleeve-likemember 23 is connected to the lower end of the nipple 22 by means of areducer 24. A short nipple 25 is connected at its upper end to the lowerend of the sleeve-like member 23 .bymeans .of a reducer 26;

The guide rod l4 extends upwardly thru the nipple 25, the reducer 26 andthe sleeve-like member '23, and is provided at its upper end with anenlarged portion 21. a guide for the guide rod I4.

A valve seat 28 is provided in the valve "hous- The nipple =25- acts asi 4 thru the outlet pipe 9, the discharge pipe 6 and the pipe line (notshown). The float In continues to rise until the upper end of the steml4, indicated by the numeral 21, engages the weight 3| on the lower endof the valve stem 30, causing the valve 29 to be seated. This stops theflow of air or other gas from the casing 7 thru the vent pipe iii. Inthe meantime a portion of the air or other gas will have been exhaustedfrom .lthe casing l=by-the rising glevel aofliquid in the easing ril.Aponsiderable volume o'f-air or other gas will remain in the upperportion of the casing 1 after the valve 29 is seated, however, and

1 the liquid level within the casing i will be deing 2|, and a taperedvalve 29 iSiSECUJJGClIiO171318- upper end of a valve stem 30. The valvestem 30 extends downwardly thru the nipple 22 and is secured at itslower end to a cylindrical weight 8 1 which is received within thesleeve-like member 23. An annular member 32, which is positronedwithin-the valve housing 26, limits the downward movement of the valve29. The valve 29 preferably is made of a tough, resilient, rubberlikematerial such as neoprene, while the valve orifices33"are 'formedin thewalls of the valve housing 2i below the valve seat 23 to permit thepassage of "air or other gas ,to or from the interror of the-casing 1"thru the valve housing 2| andthe vent pipe l9.

' The shutoff device '5 may be installed with the bottom-ofthe casing lat about'the .same elevae (iron as the top of'the draw-off connection@2, The-'elevat'ioniof the s'hutofi device T5"With .referenceto the tank[will determine the level obtaining in the tank "I at .thetime theshutoff device *5ope1atestost0pthe flow of liquid there: from. The upperendof the outlet pipe Bshould be slightly "higher than the draw-offconnection Pto prevent-air or other gas from entering the casing fl fromthe tank I.

The operation of the automatic shutofi device of the invention is asfollows:

With the tank l,full .of liquid and with the valved draw-oil 'line 2closed, .and assuming that no liquid is flowing thru the headerifromother tanksof the battery (not shown), the discharge pipe "Bwill bedisconnected from the shutoff device i5'by seating of the valve disc illon the valve seat l6 in the outlet pipe 9. Upon opening the 'valve'ddraw-01f line 2, liquid begins to flow thruthe header 3 and theriserfland enters-the casing ''1 thru the inlet pipe -.8. The valve disc Iitendsto remain seated due to .the vacuum created j by liquid moving.thru the pipe line -(not shown) butthis, tendency is at least partiallyovercome 'bythe buoyancy of the floatiil, which tends? to lift the valvedisc ll fromthe valve seat f6; Moreover the liquid entering the casingthrufthe inlet pipe ,8 .acts directly upon the underside of thevalvedisc l-l, tending to lift it, and: as the inlet pipe 8 is positionedeccentrically with respect to the valve disc I1, and the valve disc I]is secured at its center thru the ball joint 12 to the lower end of thevalve stem l3, the valve disc II tends to beft'ilted by the flow ofliquid t ru t e n et p p '8- before the other, cracking the valve andbreakingthe vacuum which tends tomaintain it firmly seated; Thereafterthe valvedisc H is unseated,

the float :Hl'rises, and liquid is caused to how A plurality of I Thusone side of the valve disc II is pu'lledqaway from the valve seat It.

terminedby-the degree to which this volume of "airsis compressed byaction of the static head of liquid within the tank I. It has beenobserved, by use-of*level-gauges, that the float IIJ ordinarilywillmotat any time be more than slightly immersed in the liquid flowingthru the casing l. ,Thusthelliquid in ,the casing .i does not tend to:be exhausted ,thru the vent pipe [9.

Thejva'lve 29inormally remains seated while liquidjis flowing'thru thecasing '1, thus preventing the passage of air or other .gas to or fromtheca'sjing 1 'thru the vent pipe l9. On the other hand air or, othergas may enterthe casing l fromfthepipe line '(not shown) thru the outletpipe 9% This will increase the volume of .air in thefupperrportion ofthe casing T and the liquid level will be forced downwardly and thefloat-l9 will'becaused to fall, thus unseating the valve 29. Thispermitsair or other gas to be evacuated f fpmufthepipeline .(not shown), whichis desirable, Air, or other-gas will be exhausted from the casing '11,thru 'thetvent pipe l9 until the pressure of theycompressed air orother gas in the upper portionfloii the casing ."l isagain balancedagainst theipressure created by the statichead of liquid intheftank. I.

As the liquid level in the tank I approaches the draw-off connection 2,due to withdrawal of liguidf'therefrom, the flow of liquid thru theheader "3,. the riser '4 andthe inlet pipe 8 tends togproceediatareduced .rate, due to a decrease in-pressure resulting from a reductionof the static .head of liquid in the tank I. Such decrease in pressurealso permits the volume of compressed air or other .gas in the upperportion of "the casing '7 "to expand, with a consequent reduction of theliquid level in the casing I. As the liquid level in the casing idecreases the float l'flfallsandthe valve 29 is unseated, permittingairto enter the casing 1 thru the vent pipe i9.

. The "liquid' level in the casing l is then equalized with theliquidlevel in the tank I, and finally,

other :gas is permitted to enter the casing "i from.

the-tank Likewise the-valve disc H is seated =without permittingair orother to enterthe pipe-line (not 'shown) thru the outlet pipe 9.

The stopcock 2G is provided for emergency use only 'ancl'normallyremains in open position.

Theiinventionmay be modified in various ways ;;without departing fromthespirit and scope thereof;

Ixclaim:

Anuautomatic shutoff device for liquid condueting;;l-ines comprising avertically disposed cyliindrical casing, an-inlet -'pipe and an outlet'pipe connected to the bottom of the casing and extending upwardly ashort distance therefrom, a. valve seat in the outlet pipe, acylindrical float received bodily within the casing, a valve stemconnected at its upper end to the float, a valve disc connected at itscenter thru a ball joint to the lower end of the valve stem, the valvedisc being of relatively large diameter and adapted to cover the ends ofboth the inlet pipe and the outlet pipe, the inlet pipe being disposedeccentrically with respect to the valve disc, a vent pipe extending thruthe top of the casing, a valve housing connected to the vent pipe, avalve seat and a valve in the valve housing, and a valve stem connectedat its upper end to the valve, the valve stem being actuated by thefloat when it is in its uppermost position to cause the valve to beseated.

TOM E. PARRISH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

